logo

Expression of type Lambda

from the theory of proveit.numbers.multiplication

In [1]:
import proveit
# Automation is not needed when building an expression:
proveit.defaults.automation = False # This will speed things up.
proveit.defaults.inline_pngs = False # Makes files smaller.
%load_expr # Load the stored expression as 'stored_expr'
# import Expression classes needed to build the expression
from proveit import Conditional, Lambda, a, b
from proveit.logic import And, InSet
from proveit.numbers import Mult, RationalNeg, RationalPos
In [2]:
# build up the expression from sub-expressions
expr = Lambda([a, b], Conditional(InSet(Mult(a, b), RationalNeg), And(InSet(a, RationalPos), InSet(b, RationalNeg))))
expr:
In [3]:
# check that the built expression is the same as the stored expression
assert expr == stored_expr
assert expr._style_id == stored_expr._style_id
print("Passed sanity check: expr matches stored_expr")
Passed sanity check: expr matches stored_expr
In [4]:
# Show the LaTeX representation of the expression for convenience if you need it.
print(stored_expr.latex())
\left(a, b\right) \mapsto \left\{\left(a \cdot b\right) \in \mathbb{Q}^- \textrm{ if } a \in \mathbb{Q}^+ ,  b \in \mathbb{Q}^-\right..
In [5]:
stored_expr.style_options()
no style options
In [6]:
# display the expression information
stored_expr.expr_info()
 core typesub-expressionsexpression
0Lambdaparameters: 11
body: 1
1Conditionalvalue: 2
condition: 3
2Operationoperator: 13
operands: 4
3Operationoperator: 5
operands: 6
4ExprTuple7, 18
5Literal
6ExprTuple8, 9
7Operationoperator: 10
operands: 11
8Operationoperator: 13
operands: 12
9Operationoperator: 13
operands: 14
10Literal
11ExprTuple15, 17
12ExprTuple15, 16
13Literal
14ExprTuple17, 18
15Variable
16Literal
17Variable
18Literal